2. PHP As A Language
PHP can be treated as a distinct language with it’s own rules
It has it’s own vocabulary - words that are familiar to the language
PHP has distinct grammatical rules
Syntax - rules to determine the composition of sentences
Semantics - the meaning and significance of words
Structure - the relationship between words
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3. Grammar and Vocaublary
Reserved Words and Keywords: if, else, ifelse; for, foreach,
while, do; and, or, xor; public, private, protected
Expressions: semicolon (;), curly braces ({...})
Arithmetic: addition (+), subtraction (-), multiplication(*)
Comparisons: equality (==), inequalities (!=), ranges (<=)
Special cases: dollar($), braces ([...]), operators (&, |, <<)
User & Built-in Constants: PHP_VERSION, E_ERROR,
E_WARNING, E_NOTICE, MY_CONSTANT
User & Built-in Functions: shuffle(), printf(), strlen()
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4. The PHP Manual - http://php.net/manual/en/
In your “assignments” workspace, create a file called “assignment-2.1.md” to
work on your answers to the following questions:
Find at least three different methods to get a random value from an array
with a built-in function (Look in Array Functions)
What does the built-in md5() function do? What is the default return
value? What built-in functions work similarly?
What is another name for “anonymous functions” in PHP and where are
they in the manual? When were they added and what was the last feature
added?
What is the default value of the “memory_limit” setting in PHP? What
value would I set to it in order to allocate ALL memory to PHP? How could I
set that value and where would I find that in the manual?
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5. Data Types - Literals
Literals are also known as Primitive Values
Representative of fixed values, such as numbers, text, etc
Four scalar types: boolean, integer float (double) & string
Two compound types: array & object
Three special types: resource, NULL & callable
What makes 1 different from 1.0?
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6. Working With Variables
Variables are storage locations with identifiers that contain values
Variables are places to store your literals. Think of a bucket.
$a_variable // This is a bucket to hold literals!
$a_variable = “some value” // Now the bucket has stuff in it
$a_variable = “something else” // The bucket remains, but a
new string is put in it
Variables in PHP are always preceded with a dollar sign ($)
Variables are not very useful empty, so they are usually followed
with an assignment operator
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7. Assignment Operators
An operator accepts one or more literals or variables, performs
an operation on them and returns the results, like a calculator.
$total = 1 // total is defined as 1
$total = $total + 1 // total is now 2
$total += 2 // total is now 4 (old total plus 2)
Orders of operation and precedence still apply here!
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8. Basic “Phrases”
Variables, basic expressions and comments:
$david = ‘awesome’; // not entirely true
Basic assignment and arithmetic operators:
$counter = 1; $counter = 2;
$counter = 1 + 1;
$counter += 2;
Getting feedback from PHP:
echo $counter;
var_dump($counter); var_export($counter);
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10. Pulling Files From Git
Open your “assignments” workspace in Cloud9
In the console, type “git remote -v” to see the repository URL for
the remote named “origin”
Connect the “assignments” repository from the class to yours:
Go to https://github.com/vcc-dig1108/assignments
Copy the repo URL to your clipboard
In the Cloud9 console, type “git remote add upstream “ (with the space at
the end) and paste the URL that you copied
Now “git remote -v” should list “origin” and “upstream”
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11. Pulling Files From Git (cont)
To get the updated code from remote use “git fetch” (try with -h)
Use “git merge” to roll that update into your local branch
You should now have the updated file “homework-2.1.md”
All instructions are in the assignment:
Open the project that you forked earlier or fork one now
Grab around 50 lines of PHP from that project that show examples of
literals, variables, function calls and other colored (important) things
If there is something that you don’t recognize, note it for later
The goal is to practice “reading” PHP grammar for now
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